qemu-io: Use BlockBackend

qemu-io should behave like a guest, therefore it should use BlockBackend
to access the block layer.

There are a couple of places where that is infeasible: First, the
bdrv_debug_* functions could theoretically be mirrored in the
BlockBackend, but since these are functions internal to the block layer,
they should not be visible externally (qemu-io as a test tool is exempt
from this).

Second, bdrv_get_info() and bdrv_get_specific_info() work on a single
BDS alone, therefore they should stay BDS-specific.

Third, bdrv_is_allocated() mainly works on a single BDS as well. Some
data may be passed through from the BDS's file (if sectors which are
apparently allocated in the file are not really allocated there but just
zero).

[Fixed conflicts around block_acct_start() usage from Fam Zheng's
"qemu-io: Account IO by aio_read and aio_write" commit.  Use
BlockBackend and blk_get_stats() instead of BlockDriverState.
--Stefan]

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1423162705-32065-14-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 6 insertions, 9 deletions

diff --git a/qemu-io.c b/qemu-io.c
index a85522a..4a3e719 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -28,7 +28,6 @@
 static char *progname;
 
 static BlockBackend *qemuio_blk;
-static BlockDriverState *qemuio_bs;
 
 /* qemu-io commands passed using -c */
 static int ncmdline;
@@ -36,10 +35,9 @@ static char **cmdline;
 
 static ReadLineState *readline_state;
 
-static int close_f(BlockDriverState *bs, int argc, char **argv)
+static int close_f(BlockBackend *blk, int argc, char **argv)
 {
     blk_unref(qemuio_blk);
-    qemuio_bs = NULL;
     qemuio_blk = NULL;
     return 0;
 }
@@ -69,7 +67,6 @@ static int openfile(char *name, int flags, QDict *opts)
         error_free(local_err);
         return 1;
     }
-    qemuio_bs = blk_bs(qemuio_blk);
 
     return 0;
 }
@@ -91,7 +88,7 @@ static void open_help(void)
 "\n");
 }
 
-static int open_f(BlockDriverState *bs, int argc, char **argv);
+static int open_f(BlockBackend *blk, int argc, char **argv);
 
 static const cmdinfo_t open_cmd = {
     .name       = "open",
@@ -115,7 +112,7 @@ static QemuOptsList empty_opts = {
     },
 };
 
-static int open_f(BlockDriverState *bs, int argc, char **argv)
+static int open_f(BlockBackend *blk, int argc, char **argv)
 {
     int flags = 0;
     int readonly = 0;
@@ -165,7 +162,7 @@ static int open_f(BlockDriverState *bs, int argc, char **argv)
     }
 }
 
-static int quit_f(BlockDriverState *bs, int argc, char **argv)
+static int quit_f(BlockBackend *blk, int argc, char **argv)
 {
     return 1;
 }
@@ -302,7 +299,7 @@ static void command_loop(void)
     char *input;
 
     for (i = 0; !done && i < ncmdline; i++) {
-        done = qemuio_command(qemuio_bs, cmdline[i]);
+        done = qemuio_command(qemuio_blk, cmdline[i]);
     }
     if (cmdline) {
         g_free(cmdline);
@@ -327,7 +324,7 @@ static void command_loop(void)
         if (input == NULL) {
             break;
         }
-        done = qemuio_command(qemuio_bs, input);
+        done = qemuio_command(qemuio_blk, input);
         g_free(input);
 
         prompted = 0;